1. Field of the Invention
This invention relates to supported metal halides and metal halide solid acids useful as catalysts for the polymerization of a feed stream containing at least one of pure monomer, C5 monomers, and C9 monomers to produce a hydrocarbon resin, to processes of preparing hydrocarbon resins using at least one of supported metal halides and metal halide solid acid catalysts, and to hydrocarbon resins produced by such processes.
2. Discussion of Background
Hydrocarbon resins are low molecular weight, thermoplastic materials prepared via thermal or catalytic polymerization. The resins may be derived from several different sources of monomers. The monomer sources include cracked petroleum distillate from oil refining, turpentine fractions (e.g., terpenes from natural product distillation), paper mill by-product streams, coal tar, and a variety of pure olefinic monomers.
The resulting hydrocarbon resins can range from viscous liquids to hard, brittle solids with colors ranging from water white to pale yellow, amber, or dark brown depending on the monomers used and the specific reaction conditions. Typically, pure monomer resins tend to be water white, C9 monomer resins tend to be brown, and C5 monomer resins tend to be yellow.
Hydrocarbon resins are used extensively as modifiers in adhesives, rubber, hot-melt coatings, printing inks, paint, flooring, and other applications. The resins are usually used to modify other materials.
Pure monomer hydrocarbon resins can be prepared by cationic polymerization of styrene-based monomers such as styrene, alpha-methyl styrene, vinyl toluene, and other alkyl substituted styrenes using Friedel-Crafts polymerization catalysts such as unsupported Lewis acids (e.g., boron trifluoride (BF3), complexes of boron trifluoride, aluminum trichloride (AlCl3), alkyl aluminum chlorides).
Similarly, aliphatic C5 hydrocarbon resins can be prepared by cationic polymerization of a cracked petroleum feed containing C5 and C6 paraffins, olefins, and diolefins also referred to as xe2x80x9cC5 monomersxe2x80x9d. These monomer streams are comprised of cationically polymerizable monomers such as 1,3-pentadiene which is the primary reactive component along with cyclopentene, pentene, 2-methyl-2-butene, 2-methyl-2-pentene, cyclopentadiene, and dicyclopentadiene. The polymerizations are catalyzed using Friedel-Crafts polymerization catalysts such as unsupported Lewis acids (e.g., boron trifluoride (BF3), complexes of boron trifluoride, aluminum trichloride (AlCl3), or alkyl aluminum chlorides). In addition to the reactive components, nonpolymerizable components in the feed include saturated hydrocarbons which can be codistilled with the unsaturated components such as pentane, cyclopentane, or 2-methylpentane. This monomer feed can be copolymerized with C4 or C5 olefins or dimers as chain transfer agents.
Also, aromatic C9 hydrocarbon resins can be prepared by cationic polymerization of aromatic C8, C9, and/or C10 unsaturated monomers derived from petroleum distillates resulting from naphtha cracking and are referred to as xe2x80x9cC9 monomersxe2x80x9d. These monomer streams are comprised of cationically polymerizable monomers such as styrene, alpha-methyl styrene, beta-methyl styrene, vinyl toluene, indene, dicyclopentadiene, divinylbenzene, and other alkyl substituted derivatives of these components. The polymerizations are catalyzed using Friedel-Crafts polymerization catalysts such as unsupported Lewis acids (e.g., boron trifluoride (BF3), complexes of boron trifluoride, aluminum trichloride (AlCl3), alkyl aluminum chlorides). In addition to the reactive components, nonpolymerizable components include aromatic hydrocarbons such as xylene, ethyl benzene, cumene, ethyl toluene, indane, methylindane, naphthalene and other similar species. These nonpolymerizable components of the feed stream can be incorporated into the resins via alkylation reactions.
Although unsupported Lewis acids are effective catalysts for the cationic polymerization reactions to produce hydrocarbon resins, they have several disadvantages. Conventional unsupported Lewis acids are single use catalysts which require processing steps to quench the reactions and neutralize the acids.
Further, conventional unsupported Lewis acids also require removal of catalyst salt residues from the resulting resin products. Once the salt residues generated from the catalyst neutralization are removed, the disposal of these residues presents an additional cost. Therefore, it is of particular interest to reduce the amount of catalyst residues, particularly halogen-containing species generated in these reactions.
Another problem involved in using conventional unsupported Lewis acid catalysts, such as AlCl3 and BF3, is that they are hazardous materials. These conventional Lewis acid catalysts generate highly corrosive acid gases on exposure to moisture, (e.g., HF, HCl).
In addition to the traditional Lewis acids, work has been done with certain solid acid catalysts. BITTLES et al., xe2x80x9cClay-Catalyzed Reactions of Olefins. I. Polymerization of Styrenexe2x80x9d, Journal of Polymer Science: Part A, Vol. 2, pp. 1221-31 (1964) and BITTLES et al., xe2x80x9cClay-Catalyzed Reactions of Olefins. II. Catalyst Acidity and Measurementxe2x80x9d, Journal of Polymer Science: Part A, Vol. 2, pp. 1847-62 (1964), the disclosures of which are herein incorporated by reference in their entireties, together disclose polymerization of styrene with acid clay catalysts to obtain polymers having molecular weights between 440 and 2000 as determined by freezing point depression of benzene solutions. These documents disclose that the catalyst was prepared for polymerization by heating under vacuum, and that if the catalyst adsorbed moisture, the activity of the catalyst could be restored by reheating under vacuum.
SALT, xe2x80x9cThe Use of Activated Clays as Catalysts in Polymerisation Processes, with Particular Reference to Polymers of Alpha Methyl Styrenexe2x80x9d, Clay Minerals Bulletin, Vol. 2, pp. 55-58 (1948), the disclosure of which is herein incorporated by reference in its entirety, discloses polymerization of styrene and/or alpha-methyl styrene by using a clay catalyst to obtain polymers that range from dimers to molecular weights of about 3000.
U.S. Pat. No. 5,561,095 to CHEN et al., the disclosure of which is herein incorporated by reference in its entirety, discloses a supported Lewis acid catalyst for polymerization of olefins, including C3-C23 alpha-olefins, to obtain polymers having number average molecular weights (Mn) ranging from about 300 to 300,000. Exemplary Lewis acid supports include silica, silica-alumina, zeolites, and clays. Example 1 of CHEN et al. discloses that a Lewis acid supported on silica is heated under vacuum.
U.S. Pat. No. 3,799,913 to WHEELER et al., the disclosure of which is herein incorporated by reference in its entirety, discloses Friedel-Crafts catalysts for polymerization of polymerizable constituents, including alpha-methyl styrene, indene, vinyl toluene and styrene, to obtain polymers having a number average molecular weight (Mn) ranging from about 350 to 1200. Zinc chloride is disclosed as one of the Friedel-Crafts catalysts.
U.S. Pat. No. 3,652,707 to SAINES, the disclosure of which is herein incorporated by reference in its entirety, discloses Friedel-Crafts metal halide catalysts for polymerization of olefin hydrocarbons, including pentene, styrene and methylstyrene, to obtain polymers having a molecular weight of from about 700 to about 2500. Zinc chloride is disclosed as one of the Friedel-Crafts metal halide catalysts.
PENG et al., xe2x80x9cElectrophilic Polymerization of 1,3-Pentadiene Initiated by Aluminum Triflatexe2x80x9d, Eur. Polym. J, Vol. 30, No. 1, pp. 69-77 (1994), the disclosure of which is herein incorporated by reference in its entirety, discloses aluminum triflate for polymerization of piperylene to obtain polymers having varying number average molecular weights.
European Patent Application 0 352 856 A1, the disclosure of which is herein incorporated by reference in its entirety, discloses use of aluminum triflate, cerium triflate, e.g., for oligomerization of C3 to C6 olefins to obtain oligomers having 6 to 24 carbon atoms.
GANDINI et al., xe2x80x9cThe Heterogeneous Cationic Polymerization of Aromatic Monomers by Aluminum Triflatexe2x80x9d, Polymer Preprints, American Chemical Society, pp. 359-360 (1996), the disclosure of which is herein incorporated by reference in its entirety, discloses use of aluminum triflate for polymerization of C9 related monomers to obtain a polymer having a number average molecular weight (Mn) around 3000. This document also discloses that aluminum triflate could be useful for the direct xe2x80x9cresinificationxe2x80x9d of mixtures of aromatic monomers and solvents arising from specific petroleum cuts.
Other documents, the disclosures of which are herein incorporated by reference in their entireties, which generally disclose the use of solid acid catalysts to polymerize monomers for the preparation of resins include U.S. Pat. No. 4,068,062 to LEPERT, U.S. Pat. No. 4,130,701 to LEPERT, U.S. Pat. No. 4,245,075 to LEPERT, and U.S. Pat. No. 4,824,921 to LUVINH.
The present invention involves the preparation of hydrocarbon resins. More particularly, the present invention involves the use of at least one of supported metal halides and metal halide solid acid catalysts to polymerize a feed of hydrocarbon monomers.
Hydrocarbon resins are prepared from at least one of pure monomer, C5 monomers, and C9 monomers using relatively environmentally benign, recyclable, at least one of supported metal halides and metal halide solid acid catalysts in which freely-associated water may have been removed. In the present invention, hydrocarbon resins are prepared by a cationic polymerization (e.g., Friedel-Crafts) wherein a feed stream containing at least one of pure monomer, C5 monomers, and C9 monomers is preferably treated with at least one of supported metal halides and metal halide solid acid catalyst.
Before use, the solid acid catalysts and/or supports may be treated to remove freely-associated water associated with the solids to maximize catalyst acidity and activity toward the polymerization. For example, prior to use, the catalyst and/or support may be calcined for a sufficient time to remove freely-associated water and/or the catalyst and/or support can be exposed to reduced atmospheric pressure. For instance, the calcining may be at a temperature up to about 700xc2x0 C., preferably at a temperature between about 50xc2x0 C. and 500xc2x0 C. The calcining may be under reduced atmospheric pressure for up to about 8 hours, preferably between about 1 hour to 4 hours.
In accordance with one aspect, the present invention is directed to a process for making a hydrocarbon resin, including polymerizing a feed stream comprising at least one member selected from the group consisting of pure monomer, C5 monomers, and C9 monomers in the presence of a supported metal halide solid acid catalyst to produce a hydrocarbon resin, wherein substantially all freely-associated water has been removed from the supported metal halide solid acid catalyst.
In accordance with another aspect, the present invention is directed to a process for making a hydrocarbon resin, including polymerizing a feed stream comprising at least one member selected from the group consisting of pure monomer, C5 monomers, and C9 monomers in the presence of ZrCl4 to produce a hydrocarbon resin.
The supported metal halide solid acid catalyst may comprise Lewis acid on clay, silica, silica-alumina, mesoporous silica, mesoporous silica-alumina, ion exchange resin, zeolite. The Lewis acid may include at least one member selected from the group consisting of ZnCl2, AlCl3, AlBr3, BF3, BCl3, FeCl3, SnCl4, TiCl4, ZrCl4, HfCl4, BiCl3, and lanthanide halides.
The clay supports may include naturally occurring clay mineral such as at least one member selected from the group consisting of kaolinite, bentonite, attapulgite, montmorillonite, clarit, Fuller""s earth, hectorite, and beidellite; synthetic clay such as at least one member selected from the group consisting of saponite and hydrotalcite; montmorillonite clay treated with at least one member selected from the group consisting of sulfuric acid and hydrochloric acid; and modified clay including at least one member selected from the group consisting of aluminum oxide pillared clay, cerium modified alumina pillared clay, and metal oxide pillared clay.
The zeolite support may include at least one member selected from the group consisting of zeolite Y, zeolite xcex2, MFI, MEL, NaX, NaY, faujasite, and mordenite.
In another feature of the present invention, the supported metal halide solid acid catalyst includes polymer grafted aluminum halide.
In accordance with another feature of the invention, the feed stream includes between about 20 wt % and 80 wt % monomers and about 80 wt % to 20 wt % of solvent. Preferably, the feed stream includes about 30 wt % to 70 wt % monomers and about 70 wt % to 30 wt % of solvent. More preferably, the feed stream includes about 50 wt % to 70 wt % monomers and about 50 wt % to 30 wt % of solvent. The solvent may include an aromatic solvent. The aromatic solvent may include at least one member selected from the group consisting of toluene, xylenes, and aromatic petroleum solvents. The solvent may include an aliphatic solvent. The invention may further include recycling the solvent.
In accordance with a feature of the invention, the feed stream includes at least C5 monomers. The feed stream may include at least C5 monomers, wherein cyclopentadiene and methylcyclopentadiene components are removed from the feed stream by heating at a temperature between about 100xc2x0 C. and 160xc2x0 C. and fractionating by distillation. The C5 monomers may include at least one member selected from the group consisting of 2-methyl-2-butene, 1-pentene, 2-methyl-1-pentene, 2-methyl-2-pentene, 2-pentene, cyclopentene, cyclohexene, 1,3-pentadiene, 1,4-pentadiene, isoprene, 1,3-hexadiene, 1,4-hexadiene, cyclopentadiene, and dicyclopentadiene. The feed stream may include at least C5 monomers, wherein the feed stream includes at least about 70 wt % of polymerizable monomers with at least about 50 wt % 1,3-pentadiene. The C5 feed stream may contain low levels of isoprene, generally contains a portion of 2-methyl-2-butene, and may contain one or more cyclodiolefins. The C5 monomers feed stream may further comprise isobutylene.
The feed stream may include at least C5 monomers, wherein the feed stream further includes up to about 40 wt % of chain transfer agent, preferably up to about 20 wt % of chain transfer agent. The chain transfer agent may include at least one member selected from the group consisting of C4 olefins, C5 olefins, dimers of C4 olefins, and dimers of C5 olefins. The chain transfer agent may include at least one member selected from the group consisting of isobutylene, 2-methyl-1-butene, 2-methyl-2-butene, dimers thereof, and oligomers thereof.
In accordance with a feature of the invention, the feed stream includes about 30 wt % to 95 wt % of C5 monomers and about 70 wt % to 5 wt % of a cofeed including at least one member selected from the group consisting of pure monomer, C9 monomers, and terpenes. Preferably, the feed stream includes about 50 wt % to 85 wt % of C5 monomers and about 50 wt % to 15 wt % of a cofeed including at least one member selected from the group consisting of pure monomer, C9 monomers, and terpenes.
In accordance with another feature of the invention, the feed stream includes at least C9 monomers. The C9 monomers may include at least one member selected from the group consisting of styrene, vinyl toluene, indene, dicyclopentadiene, and alkylated derivatives thereof. The C9 monomers may include at least about 20 wt % polymerizable unsaturated hydrocarbons. The C9 monomers may include about 30 wt % to 75 wt % polymerizable unsaturated hydrocarbons. The C9 monomers may include about 35 wt % to 70 wt % polymerizable unsaturated hydrocarbons.
In accordance with a feature of the invention, the feed stream includes about 30 wt % to 95 wt % of the C9 monomers and about 70 wt % to 5 wt % of a cofeed including at least one member selected from the group consisting of pure monomer, C5 monomers, and terpenes. Preferably, the feed stream includes about 50 wt % to 85 wt % of the C9 monomers and about 50 wt % to 15 wt % of a cofeed including at least one member selected from the group consisting of pure monomer, C5 monomers, and terpenes.
Many of the supported metal halides and metal halide solid acid catalysts function most effectively in the presence of a controlled amount of water in the monomer feed stream. In accordance with this feature of the invention, the feed stream should include less than about 500 ppm water, preferably less than about 200 ppm water, more preferably less than about 100 ppm water, and most preferably less than about 50 ppm water.
In accordance with yet another feature of the invention, the feed stream is contacted with about 0.5 wt % to 30 wt %, preferably about 1 wt % to 20 wt %, more preferably about 3 wt % to 15 wt %, and most preferably 0.5 wt % to 5 wt % of the catalyst based on monomer weight in a batch reactor.
In accordance with yet another feature of the invention, the catalyst is added to the feed stream.
In accordance with another feature of the invention, the feed stream is added to a slurry of the catalyst in solvent. The feed stream may be passed over a fixed bed of the catalyst.
In accordance with yet another feature of the invention, the feed stream is cofed with a slurry of the catalyst into a reactor.
In accordance with a feature of the invention, the polymerization is carried out as a continuous process or as a batch process. A reaction time in the batch process is about 30 minutes to 8 hours, preferably about 1 hour to 4 hours at reaction temperature.
In accordance with a feature of the invention, the feed stream is polymerized at a reaction temperature between about xe2x88x9250xc2x0 C. and 150xc2x0 C., preferably between about xe2x88x9220xc2x0 C. and 100xc2x0 C., and more preferably between about 0xc2x0 C. and 70xc2x0 C.
In accordance with another feature of the invention, the polymerization is stopped by removing the catalyst from the hydrocarbon resin. The catalyst may be removed from the hydrocarbon resin by filtration. The hydrocarbon resin may be removed from a fixed bed reactor which includes the catalyst.
In accordance with a feature of the invention, the hydrocarbon resin is stripped to remove unreacted monomers, solvents, and low molecular weight oligomers. The unreacted monomers, solvents, and low molecular weight oligomers may be recycled.
In accordance with a feature of the invention, the hydrocarbon resin is separated from a hydrocarbon resin solution.
In accordance with a feature of the invention, the hydrocarbon resin has a softening point as measured by ASTM-E28 xe2x80x9cStandard Test Method for Softening Point by Ring and Ball Apparatusxe2x80x9d, between about 5xc2x0 C. and 170xc2x0 C. The feed stream may include at least C5 monomers, wherein the softening point of the resulting hydrocarbon resin is between about 50xc2x0 C. and 150xc2x0 C. The feed stream may include at least C9 monomers, wherein the softening point of the resulting hydrocarbon resin is between about 70xc2x0 C. and 160xc2x0 C.
In accordance with a feature of the invention, the feed stream includes at least pure monomer, wherein the resulting hydrocarbon resin has a number average molecular weight (Mn) ranging from about 400 to 2000, a weight average molecular weight (Mw) ranging from about 500 to 5000, a Z average molecular weight (Mz) ranging from about 500 to 10,000, and a polydispersity (PD) as measured by Mw/Mn between about 1.2 and 3.5, where Mn, Mw, and Mz are determined by size exclusion chromatography (SEC).
In accordance with a feature of the invention, the feed stream includes at least C5 monomers, wherein the resulting hydrocarbon resin has a number average molecular weight (Mn) of about 400 to 2000, a weight average molecular weight (Mw) of about 500 to 3500, a Z average molecular weight (Mz) of about 700 to 15,000, and a polydispersity (PD) as measured by Mw/Mn between about 1.2 and 5, where Mn, Mw, and Mz are determined by size exclusion chromatography (SEC).
In accordance with another feature of the invention, the feed stream includes at least C9 monomers, wherein the resulting hydrocarbon resin has a number average molecular weight (Mn) of about 400 to 1200, a weight average molecular weight (Mw) of about 500 to 2000, a Z average molecular weight (Mz) of about 700 to 6000, and a polydispersity (PD) as measured by Mw/Mn between about 1.2 and 3.5, preferably 1.2 and 2.5, where Mn, Mw, and Mz are determined by size exclusion chromatography (SEC).
In accordance with another feature of the invention, the hydrocarbon resin is hydrogenated.